diff --git a/pkgs/development/python-modules/iapws/default.nix b/pkgs/development/python-modules/iapws/default.nix
index b146f948d7bd..43179ef17252 100644
--- a/pkgs/development/python-modules/iapws/default.nix
+++ b/pkgs/development/python-modules/iapws/default.nix
@@ -7,12 +7,12 @@
 
 buildPythonPackage rec {
   pname = "iapws";
-  version = "1.5.4";
+  version = "1.5.5";
   format = "setuptools";
 
   src = fetchPypi {
     inherit pname version;
-    hash = "sha256-nw+qOaln12/F5flfYdki4TVFMZLgK/h10HJC8T1uqlU=";
+    hash = "sha256-yG4eFxVRh3/pzrA+5BXkpJBtLlJpj/nVZWeEYJc5300=";
   };
 
   propagatedBuildInputs = [ scipy ];